Blanket-attaching device for rotary printing machines



- July 24, 1934.

G. s. ROWELL 1,967,266

BLANKET ATTACHING DEVICE FOR ROTARY PRINTING MACHINES Filed March 12. 1932 3 Sheets-Sheet 1 '7 ww 64 7 Ma m V 6* :1 :i: 3mm 7Q 75 7a 4 FIG. 4 i f,

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July 24, 1 G. s. ROWELL 1,967,265

BLANKET-ATTACHING DEVICE FOR ROTARY PRINTING MACIiINES Filed March 1952 3 Sheets-Sheet 2 FIG. 5

July 24, 1934. c. s. ROWELL BLANKET ATTACHING DEVICE FOR ROTARY PRINTING MACHINES 1932 3 Sheets-Sheet 3 Filed March 12 Patented July 24, 1934 UNITED STATES PATENT OFFICE BLANKET-ATTACHING DEVICE FOR R- TARY PRINTING MACHINES poration of Delaware Application March 12, 1932, Serial No. 598,431

33 Claims.

or intaglio, or for a transfer blanket on an offset press, or for a blanket on an impression platen. If used for attaching a printing blanket, my device may also perform the further function of acting as a distributor for the inking system.

To the above ends, I provide, on one of the rotary drums of the press, a telescoping device, the opposite ends of which are adapted tobe anchored to the end portions of a blanket curved about the drum; and I provide means for moving one of the telescoping members toward the other to .draw the blanket tightly into place.

My telescopic attaching device may comprise primarily two arcuate plates with interprojecting fingers; and if such a device has the same radius of curvature as the printing blanket on the drum, and is located at the same radial distance as the face of such blanket, the surface of the device may engage the printing rollers and, being of a proper material to receive ink, will then act to distribute such ink for the rollers. In this manner, the ink is kept in proper applying condition without requiring a large number of rollers.

My invention is hereinafter more fully explained in connection with the drawings, which illustrate it employed for holding the printing blanket and the transfer blanket of an offset press. a

. In the drawings:

Fig. 1 is a plan of the plate-carrying roller of a printing machine equipped withmy attaching 'device showing the plate in place, the inking rollers being partly broken away.

Fig. 2 is a plan of the two telescoping members of the attaching device separated.

Figs. 3 and 4 are longitudinal sections to the telescoping attachment, on the planes indicated by the corresponding numbered lines on Fig. 2.

Fig. 5 is a plan, intermediately broken away,-

of a. blanket adapted to be held by my attaching device.

Fig. 6 is a vertical section throughan ofiset' 1 Fig. 9 is an axial section through a printing drum equipped with my attaching device, in the ofiset plane indicated by the line 9--9 on Fig. 10.

Fig. 10 is a transverse section through the upper portion of the offset press of Fig. 6, showing the attaching device in the abnormal position where the blanket is being attached.

Fig. 11 is a sectional end elevation .of the form-carrying roller as the blanket is being attached.

Fig. 12 is a detail for spreading the attaching device, being a section on the line 12-12 of Fig. 11.

In Fig. 6, the numerals 10, 20 and 30 indicate respectively the form-carrying roller, the trans-.; fer roller, and the platen roller of an offset press, these rollers being mounted on the respective shafts 11, 21 and 31 mounted in suitable end frame members 40 and 41. At the top of the press is the inking system 50, comprising a supply roller 51 and two distributing rollers 52 and 53. Such inking system is suflicient for dry lithography; if the press is intended for ordinary lithography, a suitable dampening roller may be supplied.

If a suitable printing blanket-as, for instance, the image-carrying planographic plate 12-is mounted on-the drum 10, and a yielding transfer blanket 22 on the drum 20, and the parts driven in the direction indicated by the arrows in Fig. 6, impressions may be madeon paper fed along the table indicated at 44, passing between the drum 20 and thedrum 30 onto the table 45. The drive is indicated by a gear 13 (Fig. 1) on the drum 10, which may be driven by suitable driving pinion not shown. Motion may be transmitted by friction from this driven roller 10 to the rollers 20 and 30 and to the inking system.

My blanket-attaching device, when arranged for such a press as described, comprises primarily two arcuate plates 61 and 62 formed on their approximate portions, each with a set of spacially arranged projecting fingers 63 and 64. The fingers are all parallel sided, and are only slightly narrower than the spaces opposite them, the fingers 63 being opposite the spaces 66 between the fingers 64, and the fingers 64 opposite the spaces 65 between the fingers 63.

The fingers of the two plates, 61 and 62, while flush on the outside, are arranged with overlapping edges so that neither can move in or 6 out radially with reference to the other. I effect this by forming rabbets on the upper sides of some of the fingers and corresponding rabbets on the underside of the other fingers; thus, I have shown rabbets 67 on the upper sides of two of the fingers 63 and matching rabbets 68 on the under side of the adjacent fingers 64 of the other plate. Likewise, rabbets 6'? are shown on the under side of some of the fingers 63 and match with rabbets 68' on the upper side of the corresponding fingers 64. In this manner, the two arcuate plates may slide or telescopee one with reference to the other, while preserving a substantially uninterrupted arcuate exterior, as indicated in Figs. 1 and 9.

Near their outer ends, each member of the fastening device has a recess made by an inward deflection of the plate, as indicated at 71 and '72. The edge portion of the plate within the recess rigidly carriesa row of pins 73 and 74 which are-adapted to coact with rows of holes formed along the edge portions of the blanket.

The two plates 61 and 62 are provided near their extreme ends with arcuate rabbets 75 and 76 on their under sides to provide seats for the plates which, these regions, rest on correspondingly arcuate portions of the drum, as, for instance, the circular edge of the plate 15 forming the end of the drum, as shown in Fig. 9. The'two members of the telescoping attachment are suitably stiffened by webs 7'7 and 78 formed on the-r under sides.

I prefer to secure one member of the attachment fixedly to the drum. To this end, I have shown holes '79 through which screws 80 (Fig. 1) pass into the end wall of the drum 10, the far edge of the plate 61 abutting the radial surface 16 on one side of an arcuate opening into the interior of the, drum.

The movable plate 62 rests on the end members of the drum, the same as the plate. 61, but may have a slight arcuate movement limited, in the separating direction, by the radial wall 17 of the recess into the drum and in the closing direction by the ends of the fingers and the ends of the spaces between them. This movable plate is shown as. retained on the drum ends by springs which are attached at their outer ends to rods 86 mounted in some of the webs 78 of the plate 62, and at their inner ends to short rock arms 87 on a rock shaft 88 mounted in the end members of the drum.

The movable plate 62 is given a tendency to move in its closing direction, that is, toward the plate 61, by means of springs 90 anchored to a stationary rod' 91 carried in the drum and connected at their free ends to rockarms 92 on the shaft 88. This shaft carries bifurcated rock arms 93 embracing the rods 86. It results from this construction that the tension of the springs 90 is transmitted into an arcuate stress on the rods 86, and thus pulls the plate 62 into the active position shown in Fig. 6; and accordingly these springs 90 supply the .desired tension for drawingthe blanket 12 tight about the drum 10.

To release the blanket, it is only necessary to spread the plates 61 and 62,that is to say, to move the plate away from the plate 61 until it substantially abuts the drum surface 1'7, as indicated in Fig. 10. When the parts are in this position, the blanket may be easily hooked over the pins 73 and 74 of the respective members 61 and 62. For instance, with the plate 12 bent around the drum, the holes 19 may be hooked onto the stationary pins 73 and the holes 18 on the pins '74 of the movable member 62, and then, if this movable member is released, the springs 90 will draw it into active position shown in Fig. 6, effectively tensioning the blanket about the drum.

As a convenient means of spreading the attaching device to enable the demountlng and remounting of the blanket, I provide a manually slidable pin 95 in the frame member 40. Suitable thumb pressure on the head 96 of this pin shoves it into the position shown in Fig. 9, where it stands in the path of a rock arm 97 on the rock shaft 88. When the pin is in this position, the drum 10 is turned in its reverse direction until the arm 97 abuts the pin 95; then a slight further movement swings the arm 9'? and turns the rock shaft 88 which, through the bifurcated arms 93, will move the movable member 62 into the idle position shown in Fig. 10.

The arm 97 has an inclined face, as shown at 98 in Fig. 12, and this face is effective when the drum is turned in a printLng direction to engage the end of the pin 95, if it be left in its innermost position, and cam it outwardly into an idle position. Accordingly, no harm results if the operator inadvertently leaves the pin 95 in its active position, as shown in Fig. 9.

It will be understood that in the printing operation, the drum 10 rotates in the direction of the arrow, as in Fig. 6, and this operation goes on continuously irrespective of the pin 95 above mentioned. When, however, it is desired to change the plate, it is only necessary to push in the pin 95 and turn the drum in a backward direction until the arm 97 engages the pin, as indicated by the dotted lines in Fig. 10. This spreads the attaching device and frees the tension on the blanket so that it may be readily removed.

In the case of the printing drum, the attaching device 61, 62, is so formed that its exterior surface stands in the same theoretical cylindrical envelope as the exterior of the printing plate 12. Accordingly, both the plate and the attaching device engage the two transfer rollers 52 and 53 which are fed with ink from the supply roller 51. The surface of the attaching device in this instance is made to receive ink; for instance, by graining the surface or applying a suitable enamel to it; and thus the fastening device itself acts as a distributing plate coacting with the rollers to work up the ink and maintain it in proper condition for passage to the printing image.

It will be noticed that the distance between the lines of contact of the two rollers 52 and 53 with the drum is materially greater than the gap across the recesses 71 and 72. Accordingly, one or the other roller 52 or 53 is always in engagement either with the printing plate or the attaching device, and thus the speed of rotation of the rollers is maintained constant and the formation of ghost lines on the lithographic plate, if such is employed, is obviated.

I have so far described the attaching device as I use it on the plate-carrying drum. Substantiallythe same device may be used for holding and tensioning the transfer blanket, as illustrated in Figs. 6 and 8. In this instance, however, the two parts of the fastening device, here designated 161 and 162, are mounted so as to have less'external radius than the blanket 22, so that they can never contact with the attaching members 61 and 62 of the plate-carrying drum in the rotation of the machine, and thus do not receive ink from any part of the platecarrying roller, but act purely as a tensiom'ng device. Otherwise, the construction of the attaching device on the transfer roller is the same as that described. An axial section of the transfer roller on the angular line 9a-9a on Fig. 6 would be similar to Fig. 9, though the gear would be omitted. I have designated the parts within the transfer drum with reference numerals one hundred greater than those used on the printing drum, and accordingly further description thereof is regarded unnecessary.

While I have shown the attaching device in the drawings as applied to a planographic printing plate 12 or to a rubber transfer blanket 22, it will be understood it may be used for holding 7 various forms of blankets in rotary printing machines. For instance, it, might hold the flexible blanket having external projections carrying embossed prfnting strips as shown in Patent No. 1,451,204, of Clifton Chisholm, issued April 10, 1923, to The American Multigraph Company, or it might be used for holding a blanket about-a platen roller, if it were desired to employ such a blanket, in the same manner as the blanket is held on the transfer roller.

It may be noted that my co-pendng application, Serial No. 580,798, filed December 14th, 1931, and assigned to Multigraph Company, shows and claims an ink-distributing plate carried as a bridge in the gap of a printing roller and coacting with the transferring rollers of the inking system. In that application, however, the bridge did not function in any manner as a holding device for a blanket, which is the important characteristic of the bridging device of this application.

I claim:

1. In a device of the character described, the combination with a drum of a pair of telescoping members thereon, means for attaching the ends of a blanket to said members respectively, and means for moving one of said members toward the other to tension the blanket.

2. In a printing machine, the combination of a drum, a blanket adapted to extend about a portion of the drum, a pair of telescoping members, means for attaching to the ends of the blanket to said members respectively, and a spring tending to move the members toward each other.

3. The combination with a rotary drum, of a pair of telescoping members mounted on arcuate seats on the drum, and means for attaching the ends of a blanket to said members.

4. The combination with a rotary drum hav-' ing an opening with arcuate seats at the longitudinal ends thereof, an arcuate member movably mounted on said seats and having projections for attaching the end of a blanket to said member, and a spring tending to move the member in the direction to tension the blanket.

5. In a printing machine, the combination of a drum, a pair of telescoping members, means for attaching one member fixedly to the drum,

' means on the other member for anchoring the end of a blanket, and means for causing the latter member to move toward the former in an arcuate path.

6. In a device of the character described, the

- combination with a drum oi a pair of plates mounted thereon and having fingers spaced apart, the fingers at each plate being adapted to slide into the spaces between fingers on the other plate, and means for attaching a blanket to one of the plates.

'1. In a device of the character described, the combination with a drum of a pair of mutually telescoping plates mounted thereon, each plate having a longitudinal recess, a row of projecting pins carried by each plate within the recess thereof, and adapted to engage the end portions of a blanket embracing the drum and extending into the recesses of the plates.

8. In a device of the character described, the combination with a drum having an opening with guides at its ends, a plate slidably mounted on the guides and having an inwardly offset portion, a row of outwardly projecting pins carried by the plate within the oifset portion thereof, a blanket having holes near one end adapted to embrace said pins, and means for moving the plate to pull on the blanket.

9. .In a device of the character described, the combination with a. rotary drum, a pair of arcuate plates adapted to be mounted thereon and one having fingers adapted to extend into recesses of the other and stiffening webs on the inner sides of the plate.

10. The combination of a rotary drum having a recess, a pair of telescoping plates mounted in the recess and each provided with means for attaching an end of a blanket extending about the drum, a rock shaft within the drum, a rock arm on the rock shaft connected to one of the plates, and a spring acting on the rock arm.

11. As a new article of manufacture, a blanket-attaching device for a printing machine adapted to act as an ink distributor.

12. The combination, with a planographic printing plate; of a plate-attaching device adapted to act as a distributor for ink for the plate.

, 13. The combination with an inking roller, of a blanket-attaching device adapted to contact with the roller.

14. The combination of a printing blanket, a device for attaching it, and an inking roller adapted to deliver ink both to the blanket and to the attaching device.

15. The combination with a rotary drum, of a plate-attaching device thereon, and an inking roller, the surface of which is adapted to contact with a plate on the drum and with said attaching device."

16. In a printing machine, the combination of a drum having an opening, an arcuate bridge carried by the drum across the opening, said bridge having attaching means for a printing blanket, and an inking roller adapted to coact with the blanket and the bridge.

17. The combination of a drum, a telescopic device carried thereby, means for attaching both ends of a printing blanket extending about the drum to the respective members of the telescopic device, and an inking roller positioned to engage the printing blanket and the outside surface of the telescopic device as the drum rotates.

18. In a printing machine, the combination of a drum having an opening, a telescopic arcuate bridge mounted in the opening and having a flush exterior for both parts of the bridge, means for holding a printing blanket on a drum, with the printing face at the same radius as the exterior surface of the telescopic bridge and an inking roller adapted to coact with said printing face and bridge surface.

19. In a printing machine, the combination of a roller, a telescopic arcuate bridge carried by the roller, means on the two members of the bridge for attaching the two ends of a printing blanket extending about the roller, and an inking device adapted to coact with the printing face of the blanket and with the exterior of the bridge as the drum rotates.

20. In a printing machine, the combination of a drum, an arcuate plate carried thereby, and having a longitudinal recess in its exterior and a row of pins within the recess extending parallel with the drum axis, and means for moving the plate to tension a printing blanket having its ends embracing the pins, and an inking roller adapted to engage successively the exterior of the printing face on the blanket and said arcuate plate.

21. In a printing machine, the combination of a roller having a recess, a telescopic arcuate bridge within the recess, said bridge comprising a pair of plates having fingers slidably interengaging each other, means for attaching one members of the bridge to the drum, means for guiding the other member circumferentially a spring tending to move the latter member along its guide toward the fixed member, each member having an external recess and a row of pins within the recess, a printing blanket extending aboutthe drum and having holes near its ends adapted to engage said pins, and an inking roller adapted to coact with the printing face of the blanket and with the exterior of the bridge as the drum rotates, said printing face and said bridge exterior being at the same radial distance from the drum axis.

22. An attaching device for a blanket, comprising a pair of plates with interengaging fingers exposed on the exterior, and means for preventing radial movement of one plate with reference to the other while allowing it to move lengthwise of the fingers.

23. An attaching device for a blanket, comprising a pair of plates, each having spa'cially arranged fingers, the fingers of each plate adapted to slide into the space between fingers of the other plate and the edge of a finger on one plate being rabbeted on its under side, and an edge of the adjacent finger on the other plate rabbeted on its upper side.

24. An attaching device for a blanket in a printing machine, comprising a pair of arcuate plates with slidably engaging fingers and with means for securing the end of the blanket, said plates having arcuate seats on the under sides adjacent the ends and having stiffening ribs on their under sides extending beneath the various fingers.

-25. The combination of a plate-carrying drum,

a printing plate adapted to be mounted thereon, and means adapted to interlock with the plate to hold it on the drum, said means having an exterior surface at the same distance from the drum axis as the exterior surface of the plate.

26. The combination of a rotary drum, a printing plate adapted to be mounted thereon and a plate attaching device on the drum adapted to stand between the ends of the plate and having its exterior surface at the same distance from the drum axis as is the exterior surface of the plate on the drum. I

27. The combination of a rotary drum having a cavity, a plate attaching device mounted in the cavity and adapted to engage separated ends of a plate on the drum, said attching device having' an exterior surface adapted to be engaged by the inking roller which inks the plate on the drum. I

28. The combination of a plate carrying drum having a cavity, a plate mounted on the drum, means bridging the cavity and provided with projections adapted to interlock with holes in the plate, said means having an exterior surface positioned to be engaged by the ink roller.

29. An attaching device for holding a plate on a drum, comprising two members adapted to be respectively connected to the end portions of the plate and means for moving said members toward each other to tension the plate, said members having an exterior surface adapted to act as an ink distributor.

30. An attaching device for holding a plate on a drum comprising two members adapted to be respectively connected to the end portions of the plate, and means for moving said members toward each other to tension the plate, said members having an exterior surface at the same radial distance from the drum axis as the exterior of the plate.

31. The combination with a planographic printing plate of a telescoping attaching device adapted to act as an ink distributor.

32. ,The combination with a planographic printing plate of a telescoping attachingdevice positioned to engage the inking roller which inks the plate.

33. The combination with a rotary drum, a printing plate, and a telescoping attaching device adapted to engage the plate to hold it on the drum, the exterior surface of the attaching device being at the same radial distance from the axis of the drum, as is the exterior of the plate mounted on the drum.

GEORGE S. ROWELL. 

